Main Title |
Benthic foraminiferal census data from Louisiana continental shelf cores, Gulf of Mexico / |
Author |
Osterman, Lisa E.
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Other Authors |
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Publisher |
U.S. Dept. of the Interior, U.S. Geological Survey, |
Year Published |
2009 |
OCLC Number |
320122804 |
Subjects |
Foraminifera--Mexico, Gulf of ;
Drill cores--Mexico, Gulf of ;
Benthos--Mexico, Gulf of ;
Marine sediments--Mexico, Gulf of ;
Gulf of Mexico
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Internet Access |
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Holdings |
Library |
Call Number |
Additional Info |
Location |
Last Modified |
Checkout Status |
EMAD |
Internet |
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Region 6 Library/Dallas,TX |
09/20/2010 |
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Collation |
24 unnumbered pages : digital, PDF file, tables, map. |
Notes |
Cover title. Includes bibliographical references (leaf 5). |
Contents Notes |
An area of oxygen-depleted bottom- and subsurface-water (hypoxia = dissolved oxygen <2 mg/L-1) occurs seasonally on the Louisiana Shelf near the Mississippi River. The area of hypoxia, also known as the "dead zone," forms when spring and early summer freshwater flow from the Mississippi River supplies a large amount of nutrients to the shelf while creating a freshwater lens, or cap, above the shelf water. The excess nutrients cause phytoplankton blooms in the shallow shelf water. After the bloom ceases, the organic material sinks in the water column and uses up oxygen during decomposition. Thus, the subsurface waters become oxygen depleted. The seasonal dead zone exists until a reduction in freshwater flow, or overturning by storms, allows mixing of the water column to restore normal oxygen conditions (Rabalais and others, 1994, 1996; Rabalais, 2002). Since systematic measurement of the extent of the dead zone began in 1985, the overall pattern indicates that the area of the dead zone is increasing (Rabalais and Turner, 2001; Turner and others, 2005). Several studies have concluded that the expansion of the Louisiana Shelf dead zone is related to increased nutrients (primarily nitrogen, but possibly also phosphorous) in the Mississippi River drainage basin and is responsible for the degradation of Gulf of Mexico marine habitats (Goolsby and others, 2001). This paper presents the benthic foraminiferal data from 10 sediment cores collected from the Continental Shelf of Louisiana (table 1), obtained as part of an initiative to investigate the geographic and temporal extent of hypoxia prior to 1985 in the Gulf of Mexico. |
Place Published |
Reston, VA |
Access Notes |
Mode of access: Internet.; System requirements: Adobe Acrobat Reader.; Title from title screen (viewed on May 1, 2009). |
Corporate Au Added Ent |
Geological Survey (U.S.) |
Title Ser Add Ent |
U.S. Geological Survey open-file report ; 2008-1348 |
PUB Date Free Form |
2009 |
Series Title Untraced |
Open-file report ; 2008-1348 |
BIB Level |
m |
Medium |
electronic resource |
Cataloging Source |
OCLC/T |
OCLC Time Stamp |
20100915121748 |
Language |
eng |
Origin |
OCLC |
Type |
CAT |
OCLC Rec Leader |
03148cam 2200409Ia 45020 |